Camshaft sizing help

[BrettL]

Ok guys and gals I’m sure this question has Been asked a lot of times and I’ve tried searching for it but im
Not real good at navigating through here but my question is I’m wanting to install a new cam and roller lifters along with the CNC ported 440 source heads and I have a 1967 440 flat top pistons and was curious what duration and lift I could safely do with out any interference between the valves and pistons any help would be greatly appreciated. I’m looking for a little more than a mild street engine maybe an occasional run down the strip. Thanks Brett

 

[RSMS]

transmission and or torque convertor, gear ratio and car weight will need to be considered to properly make a choice. You don't want to go too big for your combo and have a total dog that's no fun to drive

 

[BrettL]

727 Hughes 2500-2800 converter 3:73 gears pretty sure the car is around 4k 1965 Dodge coronet 440 2dr Ht

 

[33 IMP]

Flattops can be anything from 7 1/2 to 11 1/2 compression ratio, depending on stroke and deck height.
Do your pistons have valve reliefs? How far down the hole are they?
We would need the accurate comp ratio (NOT what Chrysler or the piston manufacturer claims!) to begin to make a cam recommendation.
What is the cc of the heads you're gonna use?

 

[ckessel]

727 Hughes 2500-2800 converter 3:73 gears pretty sure the car is around 4k 1965 Dodge coronet 440 2dr Ht

My 65 was 3941 with half tank of fuel, iron headed 440, a/c, a/t and no driver.

 

[496 polara]

Do you mean roller lifters or rockers? If roller lifters do you mean hydraulic or solid?

What is your budget?

Hyd roller cam and lifters is cheaper than solid roller but still a $1000 not counting valve springs,pushrods,etc.

 

[BrettL]

I have the 440 source Roller rocker I want to do a roller cam and lifters with 440 source CNC ported heads I have the RPM intake and 2” full length headers I want to do a hydraulic set up im
Not a rich man but I’ve put money away for this and just need to know my limitations on sizing. I’m pretty sure the deck has been machined 10 thousands no reliefs at all for valves the internet says it should be a 10.1 ratio build year 1967 the heads do come with a dual spring but not sure the ratings on them

 

[BrettL]

I have the 440 source Roller rocker I want to do a roller cam and lifters with 440 source CNC ported heads I have the RPM intake and 2” full length headers I want to do a hydraulic set up im
Not a rich man but I’ve put money away for this and just need to know my limitations on sizing. I’m pretty sure the deck has been machined 10 thousands no reliefs at all for valves the internet says it should be a 10.1 ratio build year 1967 the heads do come with a dual spring but not sure the ratings on them

440 source says there 80cc

 

[33 IMP]

The factory rated compression ratios by Mopar are usually 1/2-1 point optimistic.
Your 67 with closed chamber heads was probably closer to 9.5 to 1.
Does it still have the standard bore 1967 pistons in it? If not, compression ratio could be anything.
For reference, we had a cast piston flat top 440 (probably late 60s/early 70s vintage) that we put a 310/.590 solid purple shaft in. We had to cut a little bitty valve relief for the intake valve..... but I don't remember the deck height.
If your pistons are .020 in the hole, you might need to be careful. If they are .100 in the hole, you can probably put in anything.... but big cam will be TOO big, lol.
Find the cam company you like, find the hydraulic roller list, and consider the second smallest listed. You will be way happier with too small a cam than too big.

 

[BrettL]

Yeah it’s 30 over bore. anyone ever had valve reliefs put in there pistons do they make a jig and a specific bit to do that? I was wanting something in the 540ish lift just not sure about duration.

 

[BrettL]

The factory rated compression ratios by Mopar are usually 1/2-1 point optimistic.
Your 67 with closed chamber heads was probably closer to 9.5 to 1.
Does it still have the standard bore 1967 pistons in it? If not, compression ratio could be anything.
For reference, we had a cast piston flat top 440 (probably late 60s/early 70s vintage) that we put a 310/.590 solid purple shaft in. We had to cut a little bitty valve relief for the intake valve..... but I don't remember the deck height.
If your pistons are .020 in the hole, you might need to be careful. If they are .100 in the hole, you can probably put in anything.... but big cam will be TOO big, lol.
Find the cam company you like, find the hydraulic roller list, and consider the second smallest listed. You will be way happier with too small a cam than too big.

That’s a pretty big duration cam I would think for the street I just really don’t want to buy new pistons if possible

 

[33 IMP]

Duration and cam timing have more effect on piston to valve than lift. At full lift, the piston is WAY down the hole.
I made a cutter, out of an old valve, used a drill motor, and an old head as a fixture, and cut my own reliefs.
Pick the lift you want, then get the shortest duration you can find with that lift.
The lift you can use will be determined by the springs and heads you use.

 

[33 IMP]

That’s a pretty big duration cam I would think for the street I just really don’t want to buy new pistons if possible

It was going in a 440/727/60 Duster, for 90% strip use. Was a beast on the street, .... with 5000 converter, and 4.56.

 

[33 IMP]

In my opinion.... it still comes down to the comp ratio you have, and the deck height. That will determine how much cam you CAN use, and how much you SHOULD use.
And without that info, we are all just spinning wheels.
Check out a comp ratio calculator to find out all the info you need to have to find out what you have, for even an educated guess.

 

[BrettL]

In my opinion.... it still comes down to the comp ratio you have, and the deck height. That will determine how much cam you CAN use, and how much you SHOULD use.
And without that info, we are all just spinning wheels.
Check out a comp ratio calculator to find out all the info you need to have to find out what you have, for even an educated guess.

Ok I will try and figure that out

 

[Geoff 2]

Need more info:
- rough idle acceptable? How rough?
- max rpm?
- what intake, carb?

 

[BrettL]

rough idle is acceptable but needs to be streetable edelbrock rpm manifold and avs 800 carb